Ensure namespaces get deleted

- can't reproduce #1 but added code to ensure namespaces get removed if they have been deleted from the cluster
- update backend-dev to run go code directly rather than building docker image
- make timings configurable and add to README
- add error handling to ranger code to avoid #1 scenario
- disable CORS by default, only needed for dev

.gitignore

@@ -12,3 +12,4 @@ gradle
 gradlew
 gradlew.bat
 .idea
+reaper

Makefile

@@ -31,9 +31,12 @@ frontend-dev:
 	cd frontend && elm-app start
 
 # Back end runs on localhost:8080, need CORS so dev front end can connect
-backend-dev: build
-	docker run --rm -it -e CORS_ENABLED=true \
-		-v $(HOME)/.kube:/root/.kube -p 8080:8080 podreaper
+# Assumes you have golang tools installed
+backend-dev:
+	go mod tidy
+	go mod download
+	go build -o reaper ./cmd/reaper
+	CORS_ENABLED=true ./reaper
 
 
 # unit testing
@@ -47,7 +50,6 @@ backend-test:
 	go test -v ./cmd/reaper
 
 
-
 # gradle shell for back end
 backend-shell: build
 	docker run --rm -it -e CORS_ENABLED=true \

README.md

@@ -29,6 +29,20 @@ The UI served by the k8s pod allows the following:
 To build and run the docker container, use `make run` then go to
 [http://localhost:8080](http://localhost:8080) for the UI.
 
+## Configuration
+
+The container can be configured using environment variables:
+
+| Variable           | Default                                                  | Description                                  |
+| ------------------ | -------------------------------------------------------- | -------------------------------------------- |
+| IGNORED_NAMESPACES | kube-system,kube-public,kube-node-lease,podreaper,docker | Reaper will ignore these namespaces          |
+| ZONE_ID            | UTC                                                      | Time Zone used by UI                         |
+| NAMESPACE_TICK     | 11s                                                      | How often to update namespace data for UI    |
+| NAMESPACES_TICK    | 17s                                                      | How often to check for new namespaces        |
+| RANGER_TICK        | 41s                                                      | How often to check limit ranges              |
+| CLOCK_TICK         | 13s                                                      | How often to update UI clock                 |
+| REAPER_TICK        | 29s                                                      | How often to check if pods need to be reaped |
+
 ## Deployment
 
 ```bash
@@ -71,7 +85,7 @@ For front end unit tests run `make frontend-test`.
 - Back end written in [Golang](https://golang.org/) and uses:
   - [client-go](https://github.com/kubernetes/client-go) go client for k8s
 - Note: Original backend was based on [Micronaut](https://micronaut.io/) and used:
-  - [Kotlin](https://kotlinlang.org/))
+  - [Kotlin](https://kotlinlang.org/)
   - [Fabric8 kubernetes client](https://github.com/fabric8io/kubernetes-client)
 
 # Links

cmd/reaper/k8s.go

@@ -140,6 +140,16 @@ func (o *k8s) removeResourceQuota(ns string, rqName string) error {
 
 // Create default limit range for namespace if it doesn't exist
 func (o *k8s) checkLimitRange(ns string) {
+	status, err := o.getStatusOf(ns)
+	if err != nil {
+		log.Printf("Ignoring limit range for %v because it has no status", ns)
+		return
+	}
+	if status != "Active" {
+		log.Printf("Ignoring limit range for %v because it has status %v", ns, status)
+		return
+	}
+
 	lr := &v1.LimitRange{
 		ObjectMeta: metav1.ObjectMeta{Name: limitRangeName},
 		Spec: v1.LimitRangeSpec{
@@ -151,7 +161,7 @@ func (o *k8s) checkLimitRange(ns string) {
 		},
 	}
 	lrs := o.clientset.CoreV1().LimitRanges(ns)
-	_, err := lrs.Get(limitRangeName, metav1.GetOptions{})
+	_, err = lrs.Get(limitRangeName, metav1.GetOptions{})
 	if err != nil {
 		log.Printf("Creating default limit range for %v", ns)
 		lrs.Create(lr)

cmd/reaper/main.go

@@ -51,7 +51,7 @@ func main() {
 		clientset = initOutOfCluster()
 	}
 
-	s := newState(*location, spec.IgnoredNamespaces, k8s{clientset: clientset})
+	s := newState(spec, *location, k8s{clientset: clientset})
 	go maintainStatus(s)
 	go maintainNamespaces(s)
 	go maintainLimitRanges(s)

cmd/reaper/namespaces.go

@@ -16,7 +16,7 @@ func maintainNamespaces(s state) {
 	tickers := map[string](chan bool){}
 
 	checkNamespaces(tickers, s) // don't wait for first tick
-	tick := time.Tick(7 * time.Second)
+	tick := time.Tick(s.Spec.NamespacesTick)
 	for {
 		select {
 		case <-tick:
@@ -48,7 +48,7 @@ func checkNamespaces(tickers map[string](chan bool), s state) {
 	// get the names of valid namespaces by removing the ignored ones
 	valid := []string{}
 	for _, next := range namespaces {
-		if !contains(s.ignoredNamespaces, next) {
+		if !contains(s.Spec.IgnoredNamespaces, next) {
 			valid = append(valid, next)
 		}
 	}
@@ -59,11 +59,19 @@ func checkNamespaces(tickers map[string](chan bool), s state) {
 			tickers[ns] = createTickerFor(ns, s)
 		}
 	}
+
+	// remove namespaces that have been deleted
+	// this will make sure it gets removed if the namespace ticker fails
+	for _, state := range <-s.getStates {
+		if !contains(valid, state.Name) {
+			s.rmNamespace <- state.Name
+		}
+	}
 }
 
 // Create a ticker to trigger updates for a particular namespace
 func createTickerFor(name string, s state) chan bool {
-	ticker := time.NewTicker(5 * time.Second)
+	ticker := time.NewTicker(s.Spec.NamespaceTick)
 	done := make(chan bool)
 	go func() {
 		for {

cmd/reaper/ranger.go

@@ -3,7 +3,7 @@ package main
 import "time"
 
 func maintainLimitRanges(s state) {
-	tick := time.Tick(60 * time.Second)
+	tick := time.Tick(s.Spec.RangerTick)
 	for {
 		select {
 		case <-tick:

cmd/reaper/reaper.go

@@ -8,7 +8,7 @@ import (
 )
 
 func reap(s state) {
-	tick := time.Tick(21 * time.Second)
+	tick := time.Tick(s.Spec.ReaperTick)
 	for {
 		select {
 		case <-tick:

cmd/reaper/state.go

@@ -5,9 +5,9 @@ import (
 )
 
 type state struct {
-	timeZone          time.Location
-	ignoredNamespaces []string
-	cluster           k8s // access to the cluster
+	Spec     Specification
+	timeZone time.Location
+	cluster  k8s // access to the cluster
 
 	// changes and updates
 	triggerNs      chan string   // signal that namespace needs to be updated
@@ -23,18 +23,18 @@ type state struct {
 	getStates  chan []nsState  // get cached namespace state
 }
 
-func newState(tz time.Location, ignored []string, cluster k8s) state {
+func newState(spec Specification, tz time.Location, cluster k8s) state {
 	s := state{
-		timeZone:          tz,
-		ignoredNamespaces: ignored,
-		cluster:           cluster,
-		triggerNs:         make(chan string),
-		rmNamespace:       make(chan string),
-		updateNsState:     make(chan nsState),
-		updateNsConfig:    make(chan nsConfig),
-		getStatus:         make(chan string),
-		getConfigs:        make(chan []nsConfig),
-		getStates:         make(chan []nsState),
+		Spec:           spec,
+		timeZone:       tz,
+		cluster:        cluster,
+		triggerNs:      make(chan string),
+		rmNamespace:    make(chan string),
+		updateNsState:  make(chan nsState),
+		updateNsConfig: make(chan nsConfig),
+		getStatus:      make(chan string),
+		getConfigs:     make(chan []nsConfig),
+		getStates:      make(chan []nsState),
 	}
 	return s
 }

cmd/reaper/status.go

@@ -13,8 +13,8 @@ func maintainStatus(s state) {
 	configs := loadConfigs(s)
 	configsChanged := false
 	states := map[string]nsState{}
-	clockTick := time.Tick(7 * time.Second) // trigger clock updates
-	cfgTick := time.Tick(17 * time.Second)  // trigger config saves
+	clockTick := time.Tick(s.Spec.ClockTick) // trigger clock updates
+	cfgTick := time.Tick(s.Spec.ReaperTick)  // trigger config saves
 
 	for {
 		select {

cmd/reaper/types.go

@@ -1,5 +1,7 @@
 package main
 
+import "time"
+
 /*
 Specification contains default configuration for this app
 that can be overridden using environment variables.
@@ -11,10 +13,18 @@ previous Kotlin/Micronaut code.
 type Specification struct {
 	IgnoredNamespaces []string `default:"kube-system,kube-public,kube-node-lease,podreaper,docker" envconfig:"ignored_namespaces"`
 	ZoneID            string   `default:"UTC" envconfig:"zone_id"`
-	CorsEnabled       bool     `default:"true" envconfig:"cors_enabled"`
+	CorsEnabled       bool     `default:"false" envconfig:"cors_enabled"`
 	CorsOrigins       []string `default:"http://localhost:3000" envconfig:"cors_origins"`
 	InCluster         bool     `default:"false" envconfig:"in_cluster"`
 	StaticFiles       string   `default:"" envconfig:"static_files"`
+
+	// timings
+	NamespaceTick  time.Duration `default:"11s" envconfig:"namespace_tick"`
+	NamespacesTick time.Duration `default:"17s" envconfig:"namespaces_tick"`
+	RangerTick     time.Duration `default:"41s" envconfig:"ranger_tick"`
+	ClockTick      time.Duration `default:"13s" envconfig:"clock_tick"`
+	ConfigTick     time.Duration `default:"17s" envconfig:"config_tick"`
+	ReaperTick     time.Duration `default:"29s" envconfig:"reaper_tick"`
 }
 
 // This is the status displayed by the UI

deploy.yaml

@@ -31,7 +31,7 @@ metadata:
 rules:
   - apiGroups: [""]
     resources: ["pods"]
-    verbs: ["get", "watch", "list", "delete"]
+    verbs: ["get", "watch", "list", "delete", "deletecollection"]
   - apiGroups: [""]
     resources: ["namespaces"]
     verbs: ["get", "list"]